The motion of the three-fragment complex consisting of heme fragment (1-25)H and apofragments (28-38) and (56-104) of horse cytochrome c reported in the previous year is interpreted as indicating that the transition occurs between the different energy states of the complex without a large change in conformation by modulation of the global cooperative interactions which evolve in the late phase of folding to stabilize the structure. Furthermore, the complex does not seem to remember the pathway through which it has folded and can unfold through reversal of any folding pathways depending on the solution conditions. Replacement of evolutionarily invariant leucine 32 even with similar non-polar residues such as isoleucine, valine, and norvaline results in a drastic decrease in the binding force of the three-fragment complex. On the other hand, evoluionarily variant leucine 35 can be replaced with isoleucine without disrupting the binding force. These observations indicate that the mechanism for the global cooperative interactions is highly specific and related to the mechanism of increasing the oxidation-reduction potential to the level of cytochrome c. Thus, the mechanism seems to be crucial not only for folding but also for the function of cytochrome c and conserved through evolution for 1.5 billion years.